Most people are aware of the term resolution in regards to digital photos. If nothing else, they know the megapixel rating of their camera, which is basically the camera’s resolution. The resolution of a digital photo is simply the pixel dimensions of the photo. A digital photo’s pixel dimensions are the determining factor in how large it can be printed and still maintain the original image quality of the photograph.
When a digital image is printed, it should have a resolution of 300ppi (pixels per inch) at the target output size of the print. This figure of 300ppi simply has to do with the optical perception of the human eye. At this 300ppi the human eye can’t detect the image pixel lines. As the resolution becomes smaller and smaller, the pixel lines become more evident, increasingly getting the “pixelated” appearance most people are aware of.
Increasing the resolution of a digital image through software will not improve image sharpness or detail. The sharpness and image detail will basically never be better than it is in the original image capture at the given resolution of the capture device, such as a digital camera. Think of resolution as a screen applied over the optical image at the time of capture. The higher the native or natural resolution of the capture device, the finer this screen mesh will be and the higher the resolution.
Increasing the native resolution of an image using software will actually degrade the original photo quality. The software will use image averaging techniques when increasing the resolution, which will never result in a finer quality visual appearance. The software has to “make up” areas of the image when building new pixels, which will never be as clear and precise as the actual light generated image characteristics. This fact is considering the use of standard over the counter image editing software such as Photoshop.
When sending a digital photo for professional photo enlargement printing, you should send the original resolution photo right from the digital camera. If you have made enhancements to the photo such as adjustments to the levels, curves, brightness or contrast, color saturation or whatever adjustments you use, this will not change the original image resolution.
The best way to build image resolution to the 300ppi level at the print output target size is to let our highly advanced software systems perform the digital photo processing. We use a two or three step digital photo processing method that will yield absolute original photo quality at whatever target photo enlargement printing size, and the image will print at 360ppi.